Carbon-based nanodots as effective electrochemical sensing tools toward the simultaneous detection of bioactive compounds in complex matrices

2020 ◽  
Vol 878 ◽  
pp. 114573
Author(s):  
Cristina Montes ◽  
M. Laura Soriano ◽  
M. Jesús Villaseñor ◽  
Ángel Ríos
2014 ◽  
Vol 809-810 ◽  
pp. 43-52
Author(s):  
Hua Hua Wang ◽  
Nan Li ◽  
Kai Li ◽  
Yuan Bu ◽  
Wen Le Dai ◽  
...  

Multiwalled carbon nanotubes (MWCNTs) as an excellent supporter covered with a thick layer of cobalt phthalocyanine (CoPc) were prepared by in-situ synthesis. Platinum particles were adopted to enhance the conductivity of CoPc-MWCNTs. The final nanocomposite Pt-CoPc-MWCNTs was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Strong aromatic π-π stacking between MWCNTs and CoPc made CoPc in-situ forming on MWCNTs. With homogeneous thickness of CoPc covered on the MWCNTs and Pt particles equally distributed, the nanocomposite was used as electrocatalyst. The electrochemical properties of the composite got researched by casting the dispersion of Pt-CoPc-MWCNTs on the glassy carbon electrode. Compared with other modified electrodes, Pt-CoPc-MWCNTs/GC electrode exhibited excellent electrochemical activity towards dopamine (DA) and uric acid (UA). Linear responses for DA and UA were obtained in the ranges of 5 to 170 μM and 5 to 100 μM, and limits of detection were 2.6 and 1.4 μM (S/N= 3), respectively. Simultaneous detection of DA and UA in the presence of ascorbic acid (AA) also displayed selective property, with no interference to each other.


Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 835 ◽  
Author(s):  
Zhaotian Cai ◽  
Yabing Ye ◽  
Xuan Wan ◽  
Jun Liu ◽  
Shihui Yang ◽  
...  

Various morphologies of iron oxide nanoparticles (Fe2O3 NPs), including cubic, thorhombic and discal shapes were synthesized by a facile meta-ion mediated hydrothermal route. To further improve the electrochemical sensing properties, discal Fe2O3 NPs with the highest electrocatalytic activity were coupled with graphene oxide (GO) nanosheets. The surface morphology, microstructures and electrochemical properties of the obtained Fe2O3 NPs and Fe2O3/GO nanohybrids were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques. As expected, the electrochemical performances were found to be highly related to morphology. The discal Fe2O3 NPs coupled with GO showed remarkable electrocatalytic activity toward the oxidation of dopamine (DA) and uric acid (UA), due to their excellent synergistic effect. The electrochemical responses of both DA and UA were linear to their concentrations in the ranges of 0.02–10 μM and 10–100 μM, with very low limits of detection (LOD) of 3.2 nM and 2.5 nM for DA and UA, respectively. Moreover, the d-Fe2O3/GO nanohybrids showed good selectivity and reproducibility. The proposed d-Fe2O3/GO/GCE realized the simultaneous detection of DA and UA in human serum and urine samples with satisfactory recoveries.


Chemosensors ◽  
2018 ◽  
Vol 6 (1) ◽  
pp. 1 ◽  
Author(s):  
Bo Si ◽  
Edward Song

Neurotransmitters are chemicals that act as messengers in the synaptic transmission process. They are essential for human health and any imbalance in their activities can cause serious mental disorders such as Parkinson’s disease, schizophrenia, and Alzheimer’s disease. Hence, monitoring the concentrations of various neurotransmitters is of great importance in studying and diagnosing such mental illnesses. Recently, many researchers have explored the use of unique materials for developing biosensors for both in vivo and ex vivo neurotransmitter detection. A combination of nanomaterials, polymers, and biomolecules were incorporated to implement such sensor devices. For in vivo detection, electrochemical sensing has been commonly applied, with fast-scan cyclic voltammetry being the most promising technique to date, due to the advantages such as easy miniaturization, simple device architecture, and high sensitivity. However, the main challenges for in vivo electrochemical neurotransmitter sensors are limited target selectivity, large background signal and noise, and device fouling and degradation over time. Therefore, achieving simultaneous detection of multiple neurotransmitters in real time with long-term stability remains the focus of research. The purpose of this review paper is to summarize the recently developed sensing techniques with the focus on neurotransmitters as the target analyte, and to discuss the outlook of simultaneous detection of multiple neurotransmitter species. This paper is organized as follows: firstly, the common materials used for developing neurotransmitter sensors are discussed. Secondly, several sensor surface modification approaches to enhance sensing performance are reviewed. Finally, we discuss recent developments in the simultaneous detection capability of multiple neurotransmitters.


2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Xiaodan Wang ◽  
Delan Gao ◽  
Mingji Li ◽  
Hongji Li ◽  
Cuiping Li ◽  
...  

2020 ◽  
Vol 16 ◽  
Author(s):  
Florina Truţă ◽  
Mihaela Tertisa ◽  
Cecilia Cristea ◽  
Florin Graur

Background: Neurotransmitters are chemical messengers with crucial implication in human body. Perturbations in concentration of neurotransmitters can affect a multitude of mental and physical functions, such as heart rate, sleep, appetite and mood. Thus, the sensitive detection of these compounds is a real need for a new generation of treatments. Method: Two important neurotransmitters namely dopamine and serotonin were investigated in this study for simultaneous detection using differential pulse voltammetry. The optimization of several surface parameters were performed in order to choose the best electrode material for electrochemical oxidation of targets. Screen printed electrodes based on carbon, gold and platinum and modified with different nanomaterials (carbon nanotubes, gold nanoparticles and carbon nanotubes decorated with gold nanoparticles) were tested. Results: Carbon-based electrodes modified with multiwall carbon nanotubes and gold nanoparticles were chosen after the optimization protocol. Linear correlations between the analytic signals obtained and the concentration of dopamine and serotonin respectively were obtained with good sensitivity and the detection limits were 0.3 µM for dopamine and 0.8 µM for serotonin with no significant reciprocal influences. Selectivity studies were also performed, as well as tests in real samples (e.g. human serum, tears and saliva) complex matrices for which acceptable recoveries were obtained. Conclusion: The results obtained within this study can be considered as an important starting point for the development of a fast and simple method for selective and highly sensitive detection of neurotransmitters, with possible applications in the diagnosis of different pathologies and for monitoring the effectiveness of the applied drug treatment.


Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2861
Author(s):  
Tomasz Koczorowski ◽  
Magdalena Cerbin-Koczorowska ◽  
Tomasz Rębiś

Phthalocyanines and porphyrazines as macrocyclic aza-analogues of well-known porphyrins were deposited on diverse carbon-based nanomaterials and investigated as sensing devices. The extended π-conjugated electron system of these macrocycles influences their ability to create stable hybrid systems with graphene or carbon nanotubes commonly based on π–π stacking interactions. During a 15-year period, the electrodes modified by deposition of these systems have been applied for the determination of diverse analytes, such as food pollutants, heavy metals, catecholamines, thiols, glucose, peroxides, some active pharmaceutical ingredients, and poisonous gases. These procedures have also taken place, on occasion, in the presence of various polymers, ionic liquids, and other moieties. In the review, studies are presented that were performed for sensing purposes, involving azaporphyrins embedded on graphene, graphene oxide or carbon nanotubes (both single and multi-walled ones). Moreover, possible methods of electrode fabrication, limits of detection of each analyte, as well as examples of macrocyclic compounds applied as sensing materials, are critically discussed.


2021 ◽  
Vol 13 (38) ◽  
pp. 4503-4514
Author(s):  
Yasan He ◽  
Xiaogeng Lin ◽  
Yuan Tang ◽  
Ling Ye

Selective electrochemical sensing via H-bonding and electrostatic interactions.


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